The present invention relates to a linear motor having a slender long stator and a shifter located so as to face the stator, for moving the shifter making use of suction or resiliency generated between an armature and a propulsion magnet.
The known conventional linear motor has a stator in the shape of almost bar having permanent magnets and a shifter having armatures, located so as to face the stator. In such a linear motor, suction or resiliency is successively generated between the armature and the permanent magnet by switching voltage applied on the armature so as to move the shifter along the stator.
In the linear motor having such structure, it is necessary to hold the armature at a regular position and to constantly maintain a micro-gap between the armature and the permanent magnet.
Then, the developments of the linear motor by which the armature can be held at a regular position are still awaited.
The present invention is linear motor having a slender long stator, a shifter located so as to face said stator, a plurality of magnets located on said stator side and a plurality of armatures located on said shifter side so as to face said magnets, for moving said shifter along said stator by switching voltage applied on said armature, said linear motor comprising:
a support portion laterally bridged between a plurality of said armatures; and
a shifter side base portion located on said shifter side, for moving along said stator in such a state that a distance between said shifter side base portion and said stator is almost constantly maintained together with a movement of said shifter; whereby said support portion is supported by said shifter side base portion so as to determine a gap between said armature and said magnet.
According to this invention, the gap between the armature and the magnet is properly maintained since the support portion laterally bridged between a plurality of the armatures is supported by the shifter side base portion although a force is generated between the armature and the magnet.
The present invention is the linear motor wherein a ditch portion is formed on a face of a side opposite to a side where said magnet is located on in said shifter side base portion, and said support portion is supported by said shifter side base portion in the state of being fitted in said ditch portion.
According to this invention, the distance between both support portions adjacent to each other of a plurality of the support portions can be properly maintained since the support portion is supported by the shifter side base portion in the state of being fitted in the ditch portion. Besides, the work, such as the work for drying is not necessary, different from the case where an adhesive is used so as to make the attachment work easy and so as to reduce the assembly error.
The present invention is the linear motor, wherein said support portion forms a continuous face with said shifter side base portion by being fitted in said ditch portion.
According to this invention, the support portion forms a continuous face with the shifter side base portion by being fitted in the ditch portion. Therefore, the interference between the outer peripheral face of the support portion or the shifter side base portion and the case can be extremely reduced even if the support portion and the shifter side base portion are stored in the case so as to assemble the shifter. Therefore, assembly work can be made easier.
The present invention is the linear motor, wherein said armature is comprised of an iron core portion provided so as to elongate from said support portion so as to closely approach said magnet and a coil fitted on said iron core portion, a projecting portion is formed at a top end portion of said iron core portion, and said coil is held so as not to be pulled out by said projecting portion.
According to this invention, the coil is held so as not to be pulled out of the iron core portion by the projecting portion. Then, the work, such as the work for drying is not necessary, different from the case where an adhesive is used so as to make the attachment work easy and so as to reduce the assembly error.
The present invention is the linear motor, wherein said shifter is in the shape of a cylinder and is fitted on the stator with a play, a plurality of magnets are symmetrically located with respect to a central axis of said stator, said armatures are symmetrically located with respect to said central axis so as to respectively face said magnets, said shifter side base portion is an annular member with said central axis as its center, and said shifter side base portion moves along said stator in such a state that a distance between said shifter side base portion and said stator is almost constantly maintained by balance of a force added by a plurality of said armatures symmetrically located with respect to said central axis.
According to this invention, the shifter is in the shape of a cylinder and is fitted on the stator with a play, a plurality of magnets are symmetrically located with respect to a central axis of the stator, the armatures are symmetrically located with respect to the central axis so as to respectively face the magnets, the shifter side base portion is an annular member with the central axis as its center, and the shifter side base portion moves along the stator in such a state that a distance between the shifter side base portion and the stator is almost constantly maintained by balance of a force added by a plurality of the armatures symmetrically located with respect to the central axis, thereby the gap between the armature and the magnet is properly maintained even if the linear motor has such a structure. Even if the magnetic force of the permanent magnet is strong or many armatures are provided in this case, the force can be compensated in the shifter side base portion, and all gaps between the armature and the magnet can be properly maintained.
The present invention is the linear motor, wherein a ditch portion is formed on an outer peripheral side of said shifter side base portion, and said support portion is supported by said shifter side base portion in the state of being fitted in said ditch portion.
According to this invention, the position of the shifter side base portion in the peripheral direction concerning the support portion can be properly determined. Besides, the work, such as the work for drying is not necessary, different from the case where an adhesive is used so as to make the attachment work easy and so as to reduce the assembly error.
The present invention is the linear motor, wherein said support portion forms a continuous face with said shifter side base portion by being fitted in said ditch portion.
According to this invention, the support portion forms a continuous face with the shifter side base portion by being fitted in the ditch portion. Therefore, the interference between the outer peripheral face of the support portion or the shifter side base portion and the case can be extremely reduced even if the support portion and the shifter side base portion are stored in the case so as to assemble the shifter. Therefore, assembly work can be made easier.
The present invention is the linear motor, wherein said armature is comprised of an iron core portion provided so as to elongate from said support portion so as to closely approach said magnet and a coil fitted on said iron core portion, a projecting portion is formed at a top end portion of said iron core portion, and said coil is held so as not to be pulled out by said projecting portion.
According to this invention, the coil is held so as not to be pulled out of the iron core portion by the projecting portion. Then, the work, such as the work for drying is not necessary, different from the case where an adhesive is used so as to make the attachment work easy and so as to reduce the assembly error.